Wrapping head for wrapping loads, particularly palletized loads, and method of operation thereof

ABSTRACT

A wrapping head for wrapping loads, particularly palletized loads, including a framework, connectable to the operating end of a handler, and supporting a reel of film made of extensible material, and diverting means, for transferring the film, unwound from the reel, towards the load. The head also includes means for cutting the film, along its feed direction, so as to obtain a first portion of film and a second portion of film that are distinct and separate from each other, and deflection means for the first portion of film, suitable to superimpose the first portion on the second portion, thus attaining, at the outlet of said wrapping head, a double-layer material band.

TECHNICAL FIELD OF THE INVENTION

The present invention regards a head for wrapping loads, moreparticularly palletized loads, and the respective wrapping method.

STATE OF THE PRIOR ART

As is known, the palletized loads consist of one or more goods arrangedon a pallet for the purpose of facilitating the movement and thetransport thereof.

In order to prevent falls or overturning of goods, during the transportof a palletized load it is provided to laterally enclosed or wrap theload itself with a layer of extensible material, for example in the formof a plastic material film.

The wrapping of a palletized load is generally carried out by means ofautomatic or semiautomatic wrapping stations, comprising means formoving a wrapping head, which carries one or more reels of suchextensible material that can be unrolled and wound around the load.

There are different types of wrapping stations.

In some types of stations, the palletized load is maintained stationary,while the wrapping head is rotated around the load.

In other types of stations, the palletized load is driven to rotatearound a longitudinal axis thereof, while the wrapping head is situatedin a fixed position at a predetermined distance from the rotatable load,and is translatable vertically and parallel to the load, so as to coverthe entire lateral surface thereof.

In this manner, the extensible material of the reel can be unrolled fromthe wrapping head, coming to form a series of spiral windings around thepalletized load, starting from a lower or upper end thereof, up toobtaining a stabilizing covering of the load.

At the end of the wrapping, the extensible material employed is cut bymeans of suitable means mounted on the wrapping head, and the film flapthus obtained is fixed to the palletized load. e.g. welded by means of asuitable buffer.

The wrapping stations briefly described above are susceptible ofimprovements, mainly with the purpose of increasing, during thetransport or during other logistical operations, the stability and thestrength of the wrapped load.

As is known, in fact, a palletized load is subjected, during thetransport, to strong stresses, accelerations or decelerations, bothlongitudinally and transversely.

In particular, if the reel of plastic material film to be wound aroundthe palletized load has a height comparable to that of the load to bepalletized, a typical example is that of the reels of film with heightof 1000 mm., and loads to be palletized that are 1200-1500 mm, high, thespiral winding of the film on the load achieves the relatively highheight superimpositions of the layers of the film, for example also onthe order of 300 mm.

Such superimposition of the layers of the film is above all verified atthe central portion of the load, since the alternating vertical movementof the wrapping head determines the execution of multiple passages atsuch zone.

As a consequence thereof, it can happen that the film exerts anexcessive pressure in the aforesaid central portion of the load,obtaining a so-called hourglass effect. i.e. with a narrower centralpart, with the consequent crushing-deformation of possible pliable goodssituated in that zone.

The strong vertical stresses sustained by the load during the transportcan temporarily cancel the weight force of the goods of the palletizedload, with the consequent reduction of the friction force between onelayer of goods and the next, and possible accidental movements betweenthe layers.

In addition, the portion of the load most subject to goods slipping onthe pallet is that in direct contact with the pallet, so that the palletdelimits an abutment surface of the goods that is nearly flat and withlow friction level, while in the upper layers the goods, usually havingnon-perfectly regular shapes, tend to offer greater slipping resistance.Presently, therefore, in order to overcome the abovementioned drawbacks,and in order to make a suitable wrapping of the palletized load, it isprovided to quite firmly wrap with the plastic material film at the baseof the load, achieving multiple windings around the pallet and aroundthe lower layer of the goods.

Such practice of firmly and repeatedly wrapping the base of thepalletized load with the plastic material film, in addition to notresolving the aforesaid problem of the “hourglass” effect of thepalletized load, involves—as can be understood—a considerable increaseof the consumption of employed film, as well as a corresponding increaseof the consumer costs of the palletized goods.

The state of the art comprises several documents which illustratemachines and methods for wrapping loads.

The document WO 2006/032065 A1 describes an apparatus for wrapping goodson a pallet, which comprises a base section for receiving a pallet anddistribution means for dispensing a material in order to wrap the goodson a pallet, the distribution means including rotary means in order toallow the material to be twisted while it is applied to the goods on thepallet.

The document US 2009/293425 A1 describes systems for tracing the use ofthe material for monitoring and optimizing the use of the extensiblefilm on a wrapping machine. Different uses are also supplied for thedata collected from the material tracing system, and different datapresentation modes are also supplied.

The document US 2018/111709 describes an apparatus, associable with awrapping machine, comprising at least one unwrapping unit for thewrapping machine for wrapping a load with a film and shuttle meansmovable along a path and adapted to receive and support an unwrappingunit to be substituted and to be disassembled from the wrapping machineand/or from a new unwrapping unit to be mounted on the wrapping machine.

The document US 2011/088359 A1 presents a wrapping machine for wrappinga tape with at least two extensible films around a product, whichcomprises a dispenser for dispensing the two extensible films withlongitudinal superimposition.

The U.S. Pat. No. 5,077,956 A describes a method for wrapping apalletized load with a tape of plastic material film whose width is afraction of the height of the load. The method is provided for a fixedtable machine with a stationary load in which the reel of film is movedaround the load and consequently unwound in order to form at least onerevolution of the tape, after which the tape of film is transverselycut, the latter terminal part of the film tape is combined with thewrapped load and the new first terminal part of the film is fixed andthe wrapped load is removed. During at least one step of the wrapping,the reel of film is moved in a path, forming a horizontal ring, and inthis step the tap of unwound film is deflected and offset in verticaldirection in order to prevent irregular folds in the film.

SUMMARY OF THE INVENTION

The technical task of the present invention is that of improving thestate of the art in the field of wrapping palletized loads.

In the context of such technical task, one object of the presentinvention is to make a wrapping head for wrapping loads which allowsovercoming the previously lamented drawbacks.

Another object of the present invention is to provide a wrapping headfor wrapping loads capable of suitably stabilizing a palletized loadwith a more limited consumption of plastic material film with respect tothe known solutions.

Still another object is to devise a wrapping head for wrapping loadswith versatile use, in order to satisfy different load wrappingrequirements.

Still another object of the present invention is to implement a wrappinghead for wrapping loads that is structurally simple and inexpensive.

A further object of the present invention is to provide a wrapping headfor wrapping loads with simple and reliable operation.

Such task and such objects are achieved by a wrapping head for wrappingloads, more particularly palletized loads, according to the presentapplication.

The wrapping head comprises a framework, connectable to the operatingend of a handler, and supporting a reel of film made of extensiblematerial.

The head also comprises diverting means for transferring the film,unwound from the reel, towards the load.

According to one aspect of the invention, the head comprises means forcutting the film, along its feed direction, so as to obtain a firstportion of film and a second portion of film that are distinct andseparate from each other.

In addition, the head comprises means for deflecting the first portionof film, suitable to superimpose the first portion on the secondportion, thus attaining, at the outlet of said wrapping head, adouble-layer material band.

In addition, the deflection means for the first portion of film areadjustable so as to obtain a partial or complete superimposition of thetwo film portions.

This solution allows at least partly obtaining a wrapping of the loadthat is more solid and thick, when desired, by using the normal filmunwound from the reel, with which one obtains, due to the aforesaidexpedients, a double-layer band, even without using a greater quantityof material.

According to a further aspect of the invention, the aforesaid deflectionmeans can be activated and deactivated in a selective manner at theuser's discretion, i.e. they can be activated only when requested,during the operation of the head.

This signifies that the user can decide, during the operation of thehead, to carry out a normal single-layer wrapping cycle, or, ifnecessary, to pass in a very simple and quick manner to a double-layerwrapping mode, for a stronger and more rigid wrapping in specific zonesof the load.

Such task and such objects are also reached by a method for wrappingloads, more particularly palletized loads, according to the presentapplication.

The wrapping method according to the invention comprises the steps ofsupplying a reel of film made of extensible material, unwinding the filmfrom the reel, cutting the film along its feed direction, so as toobtain a first portion of film and a second portion of film that aredistinct and separate from each other, and deflecting the first portionof film, so as to superimpose such first portion of film on the secondportion of film, thus attaining a double-layer material band, andwrapping the load with such band.

According to one aspect of the invention, the aforesaid step ofdeflecting the first portion of film comprises a step of deflecting suchfirst portion from a first feed direction to an intermediate feeddirection, which is deflected, with respect to such first feeddirection, by a first deflection angle.

According to another aspect of the invention, the aforesaid step ofdeflecting the first portion of film comprises a step of furtherdeflecting such first portion from the intermediate feed direction to asecond feed direction, which is deflected, with respect to suchintermediate feed direction, by a second deflection angle; inparticular, the second feed direction coincides with the feed directionof the second portion of film.

The present application refers to preferred and advantageous embodimentsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects and advantages of the present invention will be clearerfrom the following detailed description of several currently preferredembodiments, illustrated as a merely non-limiting example in theenclosed drawings, in which:

FIG. 1 is a perspective view of the wrapping head according to thepresent invention, in a specific operative step;

FIG. 2 is a further perspective view of the wrapping head, in which thefilm has been removed for greater clarity;

FIG. 3 is a top view of the wrapping head;

FIG. 4 is another top view of the wrapping head, with some parts removedfor greater clarity;

FIG. 5 is a detail of FIG. 2;

FIG. 6 is a further perspective view of the wrapping head from adifferent angle, with some parts removed and with the handler, withwhich the head is associated, illustrated in a schematic manner withdashed line;

FIG. 7 is a schematic front view of a wrapping station comprising thewrapping head according to the invention;

FIG. 8 is a front, schematic and detailed view of the deflection meansfor the wrapping head, in an initial step in which the first portion ofthe film is not yet superimposed on the second portion of the film;

FIG. 9 is a front, schematic and detailed view of the deflection meansfor the wrapping head, in a subsequent step in which the first portionof the film is superimposed on the second portion of the film, thusattaining a double-layer wrapping material; and

FIG. 10 is a schematic and detailed top view of the deflection means forthe wrapping head.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the FIG. 1, reference number 1 overall indicates ahead for wrapping loads, more particularly palletized loads, accordingto the present invention.

In the following description, by way of a non-limiting example,reference will be made to a head 1 included in a wrapping station 2(FIG. 7) in which the load 3, in particular a palletized load, is drivento rotate around a vertical or substantially vertical axis, on asuitable rotatable support platform 4, and the wrapping head 1 is fixedwith respect to the load 3, and only executes vertical or substantiallyvertical movements.

However, the present invention can also be applied to a wrapping station2 in which the load 3 is locally stationary, while the wrapping head 1is supported, and driven, to rotate around the aforesaid stationary load3.

The wrapping head 1 comprises a support framework 5.

The support framework 5 comprises a first plate 6, lower during use, anda second plate 7, upper during use, opposite the first plate 6.

The first plate 6 and the second plate 7 can be joined together by meansof elongated connection elements 8, of any type (see for example FIG.6).

As shown in the same FIG. 6, in an entirely schematic manner and onlyfor the purpose of improved comprehension, the framework 5 of the head 1is connectable to the operating end 9 of a handler 10, e.g. a robot.

The handler 10 can for example be a robot of anthropomorphic type, or aCartesian robot, or a robot of another type.

The robot 10 has the task of imparting, to the support framework 5 ofthe head 1, the necessary movements in order to execute the correctwrapping of the palletized load 3, according to a specific wrappingprogram, as is better clarified hereinbelow.

The connection between the operating end 9 of the robot 10 and theframework 5 is carried out by means of the brackets 11 fixed, forexample, to the elongated connection elements 8.

In particular, two brackets 11 can be provided, of which one is upperduring use and the other lower during use; each bracket 11 can beprovided with eyelets 12, by means of which it is possible to obtain theconnection to the operating end 9.

The framework 5 supports a reel 13 of a film 14 made of extensiblematerial suitable for the wrapping of loads, in particular palletizedloads, e.g. an extensible plastic material of type known in thisapplication type.

The wrapping head 1 can also comprise a pre-stretch group 15 of the film14 unwound from the reel 13, and intended for the wrapping of the load3.

The pre-stretch group 15 is supported by the framework 5.

The pre-stretch group 15 comprises a first roller 16 and a second roller17, rotatably supported by the framework 5, with the respective rotationaxes parallel.

The rotation axes of the rust roller 16 and of the second roller 17 areperpendicular to the planes where respectively the first plate 6 and thesecond plate 7 lie.

In one embodiment of the invention, the first roller 16 and the secondroller 17 have cylindrical or substantially cylindrical shape;nevertheless, in other embodiments, the first roller 16 and the secondroller 17 could have a different shape.

The lateral surfaces of the first roller 16 and of the second roller 17are coated with material adapted to attain high friction with the film14; for example, the lateral surfaces of the first roller 16 and of thesecond roller 17 can be coated with rubber, or another material withsuitable properties.

Such coating of the first roller 16 and of the second roller 17 couldalso be affected by surface machining, which has the purpose of furtherincreasing the friction with the film 14.

The film 14, unwound from the reel 13, is wound on the first roller 16and then on the second roller 17, in this order, before then continuingtowards the palletized load 3.

The first roller 16 and the second roller 17 comprise respective firstdriving means 18 and second driving means 19, controlled by a controlunit for operating the wrapping head 1, not represented in the figures.

The control unit is configured for commanding the first driving means 18and the second driving means 19 such that the rotation speed of thesecond roller 17 is greater than that of the first roller 16.

In this manner, the tangential speed difference of the second roller 17with respect to that of the first roller 16, to which the film 14adheres due to their special coating, causes a certain stretching of thematerial with respect to its state when it is wound in the reel 13.

Such stretching of the material of the film 14 can be carried out for atleast two reasons.

The first reason is the reduction of the consumption of material usedfor wrapping the palletized loads 3, due to the greater length of thefilm 14 given the same weight of employed material.

The second reason is that the suitably stretched material adheres in animproved manner to the external surface of the palletized load 3,causing a wrapping of improved quality. The presence of the pre-stretchgroup 15 in the wrapping head 1 according to the present invention ishowever entirely optional.

The wrapping head 1 also comprises diverting means 20 for sending thefilm 14, unwound from the reel 13 and suitably elongated by thepre-stretch group 15, towards the load 3.

In one embodiment of the invention, such diverting means 20 comprise aplurality of bars 20 a, 20 b, 20 c, 20 d, supported by the framework 5with respective longitudinal axes parallel to the axis of the reel 13.

In other words, the film 14, coming from the pre-stretch group 15,carries out, before reaching the palletized load 3, a specific path inwhich it is deflected by the bars 20 a, 20 b, 20 c, 20 d multiple times,being partially wound around the surface of the latter.

The bars 20 a, 20 b, 20 c, 20 d can be rotatably idly supported withrespect to the framework 5, or they can be fixed with respect to theframework 5 itself.

According to one aspect of the invention, the wrapping head 1 comprisesmeans 21 for cutting the film 14 along the feed and advancementdirection of the film 14 itself, so as to obtain, due to such cutting, afirst portion 22 of film 14 and a second portion 23 of film 14 that aredistinct and separate from each other, which advance together towardsthe load 3.

With reference to the path of the film 14 from the reel 13 to the load3, the cutting means 21 are interposed between the pre-stretch group 15and the diverting means 20. The cutting means 21 can for examplecomprise a blade, a heated body or other devices suitable for preciselyseparating the two aforesaid portions 22, 23 of the film 14.

Preferably, but not exclusively, the cutting means 21 are supported bythe framework 5, at about half the height with respect to the reel 13,so as to obtain a first portion 22 of film 14 and a second portion 23 offilm 14 of equal height (by height it is intended the dimension of thefilm 14 perpendicular to the direction of unwinding and feeding of thesame).

According to another version of the invention, the cutting means 21 aremovable and/or adjustable upward or downward, with respect to the heightof the reel 13, so as to obtain a first portion 22 of film 14 and asecond portion 23 of film 14 of different heights, always intending withheight the dimension of the film 14 perpendicular to the direction ofunwinding and feeding of the same.

According to another aspect of the invention, the wrapping head 1comprises deflection means 24 for deflecting the first portion 22 offilm 14, suitable to superimpose such first portion 22 on the secondportion 23 of film 14, thus attaining, at the outlet of the wrappinghead 1, a band 25 of double-layer material.

The deflection means 24 are supported by the framework 5 of the head 1.

With reference to the feed path of the film 14 from the reel 13 towardsthe palletized load 3, the deflection means 24 are provided downstreamof the cutting means 21.

In addition, the deflection means 24 are interposed between the bars 20a, 20 b, 20 c and the final bar 20 d of the diverting means 20 (see onthis matter FIG. 4, which shows the head 1 with some parts removed, andwhere a possible path P of the film 14 is illustrated, in an entirelyschematic manner, with dashed line, only for the purpose of improvedcomprehension).

The deflection means 24 modify the first feed direction D1 of the firstportion 22 of film 14, so as to bring the latter substantiallycorresponding to the second feed direction D2 of the second portion 23of film 14 (see FIGS. 8 and 9).

In other words, the deflection means 24 attain the movement of the firstfeed direction D1 of the first portion 22 of film 14 in a second feeddirection D2, parallel to the first feed direction D1.

Due to the possibilities of adjusting the deflection means 24, the firstportion 22 of film 14 can be superimposed at least partly on the secondportion 23 of film 14 and can come to be completely superimposed on thesecond portion 23 of film 14 substantially corresponding to the feeddirection of the second portion 23 of film 14.

It must be observed that the deflection means 24 attain the aforesaidmovement of the first portion 22 of film 14, without overturning orfolding, maintaining such first portion 22 parallel to itself.

The deflection means 24 comprise a plurality of deflectors 26, 27.

The deflectors 26, 27 are positioned one after the other, with referenceto the feed direction of the first portion 22 of film 14, and areconfigured for attaining the aforesaid deflection of the first feeddirection D1 of the first portion 22 of film 14.

In the embodiment of the invention illustrated in the figures, thedeflection means 24 comprise two deflectors 26, 27, and moreparticularly a first deflector 26 and a second deflector 27, aroundwhich the first portion 22 of the film 14 is wound.

The first deflector 26 is configured so as to deflect the first portion22 of the film 14 from a first feed direction D1 to an intermediate feeddirection D3 which is deflected, with respect to the first feeddirection D1, by a first deflection angle α1.

The second deflector 27 is configured so as to further deflect the firstportion 22 of the film 14 from the aforesaid intermediate feed directionD3 to the aforesaid second feed direction D2, which is deflected, withrespect to the intermediate feed direction D3, by a second deflectionangle α2. According to one version of the invention the seconddeflection angle α2 substantially corresponds to the first deflectionangle α1, but with opposite sign; for example if the first deflectionangle α1 is 120°, then the second deflection angle α2 is −120°, bringingthe portion 22 of the film 14 back to a final angle of 0°.

In some embodiments of the invention, the deflection means 24 couldcomprise further deflectors: in other words, the same result could beobtained with a number of deflectors greater than two, if the specificneeds require it (e.g. for the type of wrapping material used, or forother reasons).

In the embodiment of the invention illustrated in the figures, the firstdeflection angle α1 is 90° and the second deflection angle α2 is −90°.

The overall deflection that the first portion 22 of film 14 sustains,traversing the deflection means 24, is thus the result of the algebraicsum of the first deflection angle α1 and of the second deflection angleα2, and is thus 0°, i.e. there is a translation with respect to thefirst feed direction D1, in particular, a translation of the firstportion of film 22 parallel to itself, but moved lower, as shown in FIG.9.

According to one aspect of the invention, the first deflector 26 isselectively movable between an inactive position and an operativeposition.

When the first deflector 26 is situated in the inactive position, thewrapping head 1 can be used according to a conventional use mode, inwhich the film 14 is wound, around the load 3, in a single layer.

In this situation, the cutting means 21 can be deactivated, in order touse the single-layer film 14 directly as it is unwound from the reel 13.

If, however, the first deflector 26 is situated in the operativeposition, the wrapping head 1 is usable according to the use mode inwhich the film 14, previously cut, can be wound around the load 3 in adouble layer.

The passage of the first deflector 26 from the inactive position to theoperative position is schematically shown in FIG. 10.

In such figure, the first deflector 26 is represented with dashed linewhen it is situated in the inactive position, and it is instead shownwith solid line when it is in the operative position.

The passage of the first deflector 26 from the inactive position to theoperative position, and vice versa occurs by means of a rigidtranslation according to a direction which forms a right angle with thesymmetry axis of the reel 13.

For this purpose, the deflection means 24 comprise a linear actuator 28,associated with the aforesaid first deflector 26.

The linear actuator 28 can be of any type suitable for this purpose,e.g. electromechanical, pneumatic, oil-pressure etc.

The linear actuator 28 can be fixed, for example, to the first plate 6of the framework 5.

The first deflector 26 can for example be connected to a carriage 29slidable on guides 30 fixed to the first plate 6; the carriage 29 is, inturn, connected to the movable member 31 of the aforesaid linearactuator 28.

The first deflector 26 has essentially elongated shape.

The first deflector 26 has one end connected to the aforesaid linearactuator 28.

The first deflector 26 defines a respective first longitudinal axis 32.

The first deflector 26 has the lateral surface with shape suitable forallowing the wrapping of the film 14 around it, and also the sliding ofthe film 14 itself in the feed direction.

The first deflector 26 can for example have cylindrical shape, or in anycase be provided with a lateral surface with suitable curvature.

The first deflector 26 could also comprise, or be constituted by, arotatable roller.

The first longitudinal axis 32 of the first deflector 26 is deflected,with respect to the first feed direction D1, by a first deflection angleβ1.

In particular, according to the embodiment of the figures, the firstdeflection angle β1 is substantially equal to 45°.

According to another aspect of the invention, the deflection means 24are activatable and deactivatable in a selective manner, during theoperation of the head 1; in other words the user can decide, during theoperation of the head 1, to carry out a normal single-layer wrappingcycle, or, if necessary, to pass, in a very quick and easy manner, to adouble-layer wrapping mode, for a stronger and more rigid wrapping inspecific zones of the load.

More particularly, the second deflector 27 is selectively movablebetween a first position, in which it does not carry out any deflectionof the first portion 22 of film 14, and a second position, in which itcarries out the deflection of the first portion 22 of film 14, so as tobring such first portion 22 in superimposition on the second portion 23,thus attaining, at the outlet of the wrapping head 1, a band 25 ofdouble-layer material.

As shown in FIGS. 8 and 9, the passage of the second deflector 27 fromthe first position to the second position, and vice versa, occurs bymeans of a rigid translation of the second deflector 27 according to adirection parallel to the symmetry axis of the reel 13 (i.e. during use,and in most wrapping applications, according to a vertical orsubstantially vertical direction).

For this purpose, the deflection means 24 comprise means 33 fortranslating the second deflector 27 between the aforesaid first positionand second position.

The translation means 33 can be of any type suitable for this purpose.

For example, the translation means 33 can comprise a guide member 34fixed to the framework 5, to which a slider 35 is in turn connected in aslidable manner.

As shown in the detail of FIG. 5, a support 36 is fixed to the slider35; such support 36 is in turn associated with the second deflector 27.

The slider 35 is actuated to slide along the guide member 34 by linearactuation means which can be of any type suitable for the application,e.g. electromechanical, pneumatic, oil-pressure, etcetera.

It must be observed therefore that the deflection of the first portion22 of the film 14 can be adjusted and in this manner also thesuperimposition of the first portion 22 with respect to the secondportion 23 can be adjusted. The second deflector 27, being moved bymeans of the translation means 33, can render the superimposition of thefirst portion 22 with respect to the second portion 23 partial orcomplete.

In addition, given that also the cutting means 21 are movable andadjustable upward or downward, with respect to the height of the reel13, also the two portions 22, 23 of the film 14 can be varied.

Hence, the maximum flexibility is obtained for making the wrapping 2 forthe load 3, with portions 22, 23 equivalent or not equivalent andpartial or complete superimpositions.

The second deflector 27 has essentially elongated shape, and defines arespective second longitudinal axis 37.

As with the first deflector 26, also the second deflector 27 has thelateral surface with shape suitable for allowing the wrapping of thefilm 14 around it, and also the sliding of the film 14 itself in thefeed direction.

The second deflector 27 can for example have cylindrical shape, or inany case be provided with a lateral surface with suitable curvature.

The second deflector 27 could also comprise or be constituted by arotatable roller.

The second longitudinal axis 37 of the second deflector 27 is deflected,with respect to the intermediate feed direction D3, by a seconddeflection angle β2.

In particular, according to the embodiment of the figures, also thesecond deflection angle β2 is substantially equal to −45°.

As can be observed in the particular case of FIG. 9, in order to obtainthe desired result, the rust deflection angle β1 of the first deflector26 is substantially equal to half of the rust deflection angle α1, likethe second deflection angle β2 of the second deflector 27 issubstantially equal to half of the second deflection angle α2.

In other cases, for example with a first deflection angle α1 of 120° anda second deflection angle α2 of −120°, the deflection angle β1 of thefirst deflector 26 is substantially equal to half of the supplementaryangle of the first deflection angle α1, i.e. it is substantially equalto 30°, and the same calculation holds true for the deflection angle β2of the second deflector 27, which is substantially equal to half of thesupplementary angle of the second deflection angle α2, i.e. it issubstantially equal to −30°, with respect to the intermediate feeddirection D3.

In one embodiment of the invention, the deflection means 20 can comprisea further bar 20 e, supported by the framework 5 and placed downstreamof the bar 20 d, with reference to the feed direction of the film 14,which allows directing, with a suitable winding angle, the first portion22 of the film 14 towards the first deflector 26.

In light of that described above, the operation of the wrapping head 1according to the invention is intuitive.

In a preliminary step of arranging the head 1, if in the wrapping it isdesired to use, for some zones of the load 3, the double-layer wrappingmode, the first deflector 26 is translated into its operative position.

As is observed, for example, in FIGS. 1, 8, 10, when the first deflector26 is situated in its operative position, it is approached to the seconddeflector 27, which is situated in its first position; moreparticularly, as shown in FIG. 8, the second deflector 27 is situated(with reference to the plane of the floor, on which the load 3 issupported) at a height slightly greater than that of the first deflector26, in a manner such that the first portion 22 of film 14 is wound, insuccession, on the external surface of the first deflector 26 and of thesecond deflector 27 so as to substantially not sustain any deflectionwith respect to the first feed direction D1, due to the mutualpositioning between the first deflector 26 and the second deflector 27.

In this operating configuration, the head 1 can carry out the wrappingof the load 3 with a single layer of film 14.

More particularly, the first portion 22 and the second portion 23, evenif previously separated by the cutting means 21, are fed parallel, orsubstantially parallel, to each other, and hence wound around the load 3essentially as if they constituted a film that is intact, even if with alongitudinal cut.

When it is desired, however, to carry out the wrapping of the load 3with double-layer mode—e.g. in some portions of the load, such as thebase—the second deflector 27 is translated from the first position tothe second position, as shown in FIG. 8 (in which the second deflectoris represented with a dashed line) and in FIG. 9.

In particular—with reference to a normal situation of use of the head1—in the passage from the first position to the second position, thesecond deflector 27 carries out a downward translation.

In substance, the second deflector 27 travels a section equal to thedistance between the upper edge of the first portion 22 of the film 14and the upper edge of the second portion 23 of the film 14.

In this manner, the first portion 22 of the film 14, being wound aroundthe first deflector 26, is deflected from the first feed direction D1 tothe intermediate feed direction D3, which is deflected, with respect tothe first feed direction D1, by the first deflection angle α1 (which is,in particular, substantially equal to 90°).

In addition, the same first portion 22 of the film 14, being woundaround the second deflector 27, is deflected from the intermediate feeddirection D3 to the second feed direction D2 which is deflected, withrespect to the intermediate feed direction D3, by the second deflectionangle α2, substantially equal to −90°.

In this manner, the first portion 22 of film 14 is superimposed on thesecond portion 23, and both are fed along the second feed direction D2,attaining a band 25 of double-layer material.

If it is desired, after having carried out, around the load 3, a certainnumber of windings with the aforesaid band 25 of double-layer material,the second deflector 27 can be brought back to its first position ofFIG. 8, in a manner such that the first portion 22 and the secondportion 23 of film can be newly fed one parallel to the other in thesingle-layer configuration.

Also forming the object of the present invention is a method forwrapping loads, in particular palletized loads.

The method according to the present invention comprises the steps of:

supplying a reel 13 of film 14 made of extensible material;

unwinding the film 14 from the reel 13;

cutting the film 14 along its feed direction, so as to obtain a firstportion 22 of film 14 and a second portion 23 of film 14 that aredistinct and separate from each other; deflecting the first portion 22of film 14, so as to superimpose the first portion 22 of film 14 on thesecond portion 23 of film 14, so as to attain a band 25 of double-layermaterial; and

wrapping the load 3 with such band 25 of double-layer material.

According to one aspect of the invention, such step of deflecting thefirst portion 22 of film 14 comprises, more in detail, a step ofdeflecting the first portion 22 from a first feed direction D1 to anintermediate feed direction D3, which is deflected, with respect to saidfirst feed direction D1, by a first deflection angle α1.

According to another aspect of the invention, the aforesaid step ofdeflecting the first portion 22 of film 14 further comprises a step ofdeflecting the first portion 22 from the aforesaid intermediate feeddirection D3 to a second feed direction D2 which is deflected, withrespect to the intermediate feed direction, by a second deflectionangle. The second feed direction D2 coincides with the feed direction ofthe second portion 23 of film 14.

In one embodiment of particular practical interest of the methodaccording to the invention, the first deflection angle α1 issubstantially equal to 90° and the second deflection angle α2 issubstantially equal to −90°.

The invention as conceived allows attaining important technicaladvantages.

As seen, first of all the wrapping head 1 according to the presentinvention has the considerably advantage of being able to modify, evenduring the winding of a load, the working mode, passing from thesingle-layer configuration to the double-layer wrapping configuration,and vice versa, in relation to the different packaging requirements.

Only by way of a non-limiting example, the double-layer wrapping modecan be used when the base of the load 3 is wrapped, while thesingle-layer wrapping mode can be used when the central portion of thesame load 3 is wrapped.

In addition thereto, it is underlined that, due to the solutionaccording to the present invention, the double-layer wrapping is carriedout with consumption of further material with respect to thesingle-layer solution, since the same film 14 is used, longitudinallycut into two portions 22, 23 and superimposed on each other.

In addition, it is observed that, also in the double-layer wrappingmode, the wrapping is carried out by always directing towards the load 3the same face of the film 14.

Indeed, the double deflection sustained by the first portion 22 (forwinding on the first deflector 26 and then on the second deflector 27)in substance determines a double overturning of the film 14 which, atthe outlet of the deflection means 24, has the same orientation that ithad before traversing the aforesaid deflection means 24.

This circumstance is important since it is known that, usually, the twofaces of the film 14 used in this application type are not identical,but rather the one preferably directed towards the load 3 has betteradhesion characteristics. For example, such better adhesioncharacteristics are due to the presence of a glue on the face of thefilm 14 directed towards the load 3.

These results are obtained with a structurally simple and inexpensivetechnical solution, that is also easy to use and versatile.

It was thus seen that the invention attains the proposed objects.

The invention thus conceived is susceptible of numerous modificationsand variations, all falling within the scope of the inventive concept.

In addition, all the details can be substituted by technicallyequivalent elements.

In practice, the materials used, as well as the contingent shapes andsizes, can be of any type in accordance with the requirements withoutdeparting from the protective scope of the following claims.

1. A wrapping head for wrapping loads, particularly palletized loads,comprising a framework, connectable to the operating end of a handler,and supporting a reel of film made of extensible material, and divertingmeans for transferring the film, unwound from the reel, towards theload, further comprising means for cutting the film, along its feeddirection, so as to obtain a first portion of film and a second portionof film that are distinct and separate from each other, and deflectionmeans for the first portion of film, suitable to move said firstportion, parallel to itself, in order to at least partly superimposesaid first portion on said second portion.
 2. The wrapping headaccording to claim 1, wherein said deflection means are provided withadjustment means for partly or completely superimposing the firstportion on the second portion, thus attaining, at the outlet of saidwrapping head, a band of material that is partly or completelydouble-layer.
 3. The wrapping head according to claim 1, wherein saiddeflection means comprise a first deflector and a second deflector,around which the first portion of the film is wound.
 4. The wrappinghead according to claim 3, wherein said first deflector is configured soas to deflect the first portion of the film from a first feed directionto an intermediate feed direction which is tilted, with respect to saidfirst feed direction, by a first deflection angle.
 5. The wrapping headaccording to claim 4, wherein said second deflector is configured so asto further deflect the first portion of the film from said intermediatefeed direction to a second feed direction which is tilted, with respectto said intermediate feed direction, by a second deflection angle, saidsecond feed direction substantially corresponding to the feed directionof the second portion of film.
 6. The wrapping head according to claim5, wherein said first deflection angle and said second deflection angleare substantially equal and with opposite sign.
 7. The wrapping headaccording to claim 6, wherein said first deflection angle issubstantially equal to 90° and said second deflection angle issubstantially equal to −90°.
 8. The wrapping head according to claim 4,wherein said first deflector has essentially elongated shape, and itdefines a respective first longitudinal axis tilted, with respect tosaid first feed direction, by a first tilt angle.
 9. The wrapping headaccording to claim 8, wherein said second deflector has essentiallyelongated shape, and it defines a respective second longitudinal axistilted, with respect to said intermediate feed direction, by a secondtilt angle.
 10. The wrapping head according to claim 9, wherein saidfirst tilt angle is substantially equal to half the supplementary angleof the first deflection angle and wherein said second tilt angle issubstantially equal to half the supplementary angle of the seconddeflection angle.
 11. The wrapping head according to claim 10, whereinsaid first tilt angle is substantially equal to 45° and said second tiltangle is substantially equal to −45°.
 12. The wrapping head according toclaim 4, wherein said deflection means can be activated or deactivatedin a selective manner during the operation of said head, so as to selectcarrying out a normal single-layer wrapping cycle, or a double-layerwrapping cycle.
 13. The wrapping head according to claim 12, whereinsaid second deflector is selectively movable between a first position,in which it does not carry out any deflection of the first portion ofthe film, and a second position, in which it carries out the deflectionof the first portion of film, so as to bring the first portion to besuperimposed on the second portion, thus attaining, at the outlet ofsaid wrapping head, a band of double-layer material.
 14. The wrappinghead according to claim 13, wherein the passage of said second deflectorfrom said first position to said second position, and vice versa, occursby means of a rigid translation of said second deflector according to adirection parallel to the symmetry axis of the reel of film.
 15. Thewrapping head according to claim 14, wherein said deflection meanscomprise translation means for translating said second deflector,between said first position and second position, said translation meanscomprising a guide member fixed to said framework, to which a slider isin turn connected in a slidable manner, said slider associated with saiddeflector, said slider being actuated to slide along said guide memberby linear actuation means.
 16. The wrapping head according to claim 3,wherein said first deflector is selectively movable between an inactiveposition and an operative position, such that when said first deflectoris situated in said inactive position, the wrapping head can be usedaccording to a conventional use mode, in which the film is wound, aroundthe load, in a single layer, while when said first deflector is situatedin said operative position, the wrapping head is usable according to theuse mode in which the film, previously cut, can be wound, around theload, in a double layer.
 17. The wrapping head according to claim 16,wherein the passage of said first deflector from said inactive positionto said operative position, and vice versa, occurs by means of a rigidtranslation according to a direction that forms a right angle with thesymmetry axis of the reel of film.
 18. The wrapping head according toclaim 1, wherein said cutting means are movable and/or adjustable upwardor downward, with respect to the height of the reel, so as to obtain afirst portion of film and a second portion of film of different heights,the height being intended as the dimension of the film perpendicular tothe unwinding and feeding direction thereof.
 19. A method for wrappingloads, comprising the steps of: supplying a reel of film made ofextensible material; unwinding the film from the reel; characterized inthat it comprises cutting the film along its feed direction, so as toobtain a first portion of film and a second portion of film that aredistinct and separate from each other; deflecting said first portion offilm, parallel to itself, so as to at least partly superimpose saidfirst portion of film on said second portion of film, thus at leastpartly attaining a band of double-layer material; and wrapping the loadwith said band.
 20. The wrapping method according to claim 19, whereinsaid step of deflecting said first portion of film comprises a step ofdeflecting said first portion from a first feed direction to anintermediate feed direction which is tilted, with respect to said firstfeed direction, by a first deflection angle.
 21. The wrapping methodaccording to claim 20, wherein said step of deflecting said firstportion of film comprises a step of further deflecting said firstportion from said intermediate feed direction to a second feed directionwhich is tilted, with respect to said intermediate feed direction, by asecond deflection angle, said second feed direction substantiallycorresponding to the feed direction of said second portion of film. 22.The wrapping method according to claim 21, wherein said first deflectionangle is substantially equal to 90° and said second deflection angle issubstantially equal to −90°.